Question

You roll a standard number cube. Find P(number greater than 1)

Answer 1

Chance of it being a 1?

Answer 2

i think so lol

Answer 3

it gives answers to choose from a)6/5 b)5/6 c)1/6 d)1

Answer 4

Heh, P(not 1) is 1-P(1)

Answer 5

i'm confused lol

Answer 6

Do you know what the probability of rolling a 1 is?

Answer 7

1/6 ?

Answer 8

Right, so what you want is P(not 1), right?

Answer 9

right

Answer 10

a number greater then 1 though

Answer 11

That's the same as (not 1)

Answer 12

oh lol

Answer 13

The probability of an event ocurring and not ocurring must sum to 1

Answer 14

still confused lol

Answer 15

Why is the probability of rolling a 1 equal to 1/6?

Answer 16

because a normal cube goes up to 6

Answer 17

Right, there are 6 possible outcomes and you want only one of them ->1/6

So the total probability is 6/6 ie 1

So if you are not getting a 1, you are getting any one of the others, what must be the probability of that?

Answer 18

1/6?

Answer 19

That is the probability of getting a 1 (or a 2, or a 3 etc), a specific number.

What we want is the probability of it being ANYTHING other than 1.

Answer 20

How many possibilities is that?

Answer 21

5/6 ?

Answer 22

Bingo!

1/6 + 5/6 = 1

P(event) + P(not event) = 1

Answer 23

thanks (:

Answer 24

ur welcome